A series of di-, tri- and tetranuclear lanthanide clusters with slow magnetic relaxation for Dy-2 and Dy-4

A series of dinuclear, trinuclear and tetranuclear lanthanide complexes, formulated as [Nd-2(Acc)(6)(H2O)(4)](3) [Nd-2(Acc)(6)(H2O)(6)]center dot Cl-24 center dot 8H(2)O (1), [Dy-2(Acc)(4)(H2O)(8)]center dot Cl-6 center dot 5.89H(2)O (2), [Ln(3)(Acc)(10)(H2O)(6)]center dot(ClO4)(9)center dot 4H(2)O (Ln La, (3); Nd, (4)) and [Ln(4)(mu(3)-OH)(4)(Acc)(6)(H2O)(7)(ClO4)]center dot(ClO4)(7)center dot 11H(2)O (Ln Dy, (5); Yb, (6)), have been synthesized through the reaction of 1-amino cyclohexanel-carboxylic acid (Acc) and LnCl(3)/Ln(ClO4)(3). Crystal structure analysis reveals that complexes 1 and 2 show dinuclear lanthanide cluster, complexes 3 and 4 have three lanthanide ions with a linear arrangement, while complexes 5 and 6 exhibit a cubane-like [Ln(4)(mu 3-OH)(4)](8+) (Ln Dy and Yb) cluster core. Their structural variations are attributed to the effect of anions and lanthanide contraction. Magnetic studies indicate that the Dy-2 and Dy-4 clusters exhibit slow relaxation of magnetization.